I see. So we have ZEQ2 to thank for those awesome cliffsPoking fun at the apparent design flow for the cliff generation & shading by utilizing normal/displacement mapping along with an ambient factor (or shading band) -- something that N-J and Adam were standardizing a process for when they were working on the ZEQ2 project in 2007.
http://bradsmithee.com/backup/adamburry.info/cliffsamplecomparision.jpg
http://bradsmithee.com/backup/adamburry.info/cliffsamplecomparision2.jpg
http://bradsmithee.com/backup/adamburry.info/samplecliff.jpg
http://bradsmithee.com/backup/adamburry.info/scenebig2.jpg
http://bradsmithee.com/backup/adamburry.info/wipcliff.jpg
Probably something extremely commonplace in geographical 3D workflows these days anyhow. Could even be using controlled-noise peturbation instead of displacement.
Honestly, I was just waxing nostalgic.